With the development of a mobile telecommunications system, the system can provide increasingly high service quality. An air interface throughput keeps increasing; however, with the increase in the number of users and the growth of data services, the air interface throughput remains a development bottleneck. To relieve congestion of a mobile network, a network operator needs to deploy more base stations to improve a network capacity, which, however, definitely increases an investment cost and a maintenance cost. To solve such a problem, more network operators choose a manner of mobile data offloading to offload a part of data in the mobile network to another available access technology, which serves as a complement of the mobile network. At present, main complementary network technologies used for mobile data offloading include a Wi-Fi (Wireless Fidelity, wireless fidelity), a home base station, and the like.
LTE (Long Term Evolution, Long Term Evolution) network is a mobile telecommunication network that is being actively researched by various manufacturers in the 3GPP (3rd Generation Partnership Program, 3rd Generation Partnership Program) organization and is an evolved network of a UMTS (Universal Mobile Telecommunications System, Universal Mobile Telecommunications System). LTE aims at providing a low-cost network capable of reducing a delay, improving a user data rate, and increasing a system capacity and coverage. An eNB (evolved NodeB, evolved NodeB) is deployed on an air interface of the LTE network, so that a UE (User Equipment, user equipment) implements air interface transmission of a mobile service by using the eNB.
Wi-Fi is a standard of a WLAN (Wireless Local Area Network, wireless local area network) and is a communications network formed by a wireless network interface card and an AP (Access Point, access point). An AP, generally called a network bridge or an access point, is a conventional bridge between a wired local area network and a wireless local area network. Therefore, any user equipment disposed with a wireless network interface card can share resources of a wired local area network and even a wide area network by using the AP. A working principle thereof is equivalent to that of a HUB with a built-in radio transmitter or a router with a built-in radio transmitter. A wireless network interface card is a client device responsible for receiving a signal transmitted by the AP.
On a communications network, when a UE moves from a base station to a coverage area of another base station, the UE needs to perform a cell handover, so as to maintain service continuity. On a network integrating LTE and Wi-Fi, when a handover is performed, transmission of a UE on a source base station and a source Wi-Fi AP stops; after the handover is complete, a target base station adds a new Wi-Fi AP for the UE; before the target base station adds a new Wi-Fi AP, the UE needs to perform detection and measurement, so that an appropriate Wi-Fi AP can be selected and configured for the UE. This consumes a long time and makes Wi-Fi data transmission interrupted for a long time.